1,720,979 research outputs found
Optimisation of suspended-deck bridge design: a case study
No full textThe study deals with the optimum suspended-deck bridge (i.e. suspension, cable-stayed and tied-arch bridges) design through cable adjustment. An easy linear analysis procedure is proposed based on the Force Equilibrium Method. It includes a preliminary identification of the objective function through a mathematical Sensitivity Analysis (SA) and an optimisation procedure based on the Influence Matrix Method (IMM). It neglects time-dependent effects and geometric nonlinearities. In spite of its simplicity, the proposed approach has proven to be good and functional and, on account of its straightforward physical meaning, also suitable to practising engineers. It aims to obtain an optimal moment distribution on the deck with a reasonable increment in the cable forces. An optimal distribution of stress in the cables can also be pursued. The proposed procedure is rather general and can be applied to both the design and the construction stages. The Gravina Bridge in Matera, Italy, is used as a model to illustrate the method and its applicability to practical engineering problems
Identification and Numerical Analysis of an Experimental Model of the Skyscraper ENEL in Naples
No full textNonlinear Analysis and Retrofitting of Historical Arch Bridges
No full textThe paper deals with the collapse behavior of a historical masonry arch bridge subject to combined seismic loads, by means of the limit analysis and shakedown theorems. The assessment of the collapse loads and shakedown multiplier have been analyzed using lower bound theorems of the limit analysis and shakedown theory. The retrofitting consists in the application of CFRP strips on the extrados of the arch with a significant increase of the collapses and shakedown multipliers. The results of a FEM analysis have been achieved with ANSYS code involving the non-linear material behavior and the structural role of the spandrel walls and filling
Fast and Optimized Calculation of the Cable Pretension Forces in Arch Bridges With Suspended Deck
No full textThis paper presents with an effective and fast approach to the optimization of the pretension forces in arched bridges with suspended deck, which makes use of the influence matrix method (IMM). The given cable-tensioning procedure leads to a linear system of equations with a reduced number of unknowns and can be effectively implemented within active control procedures that handle time-varying loading conditions. This method produces a target bending moment distribution (TBMD) over the structure, which significantly mitigates the state of stress of the deck. Numerical simulations referred to a Nielsen arch bridge illustrate the versatility of the proposed approach when dealing with different loading conditions
Loading noise effects on the system identification of composite structures by dynamic tests with vibrodyne
No full textThe design of new composite structures, and the system identification of existing structures strengthened through the application of composite materials, often require dynamic tests executed with the assistance of accurate forcing devices. The present paper presents a characterization of the force time-histories that can be applied through a vibrodyne, an electro-mechanical excitation machine that is able to generate vibrations, with known frequency and amplitude. Such a device is frequently employed when dealing the experimental modal analysis of composite structures at different scales. We conduct an experimental study on the forcing functions generated by a vibrodyne, and the mismatches between such loading histories and the theoretical sinusoidal profiles. Next, we study the effects of such mismatches on the simulated dynamic response of a simple structural model. Based on the results of such a study, we outline a procedure for building up a database of the real forcing functions applied by a vibrodyne, over a wide range of operating conditions. Such a tool can play a key role when conducting dynamical tests on next-generation composite structures through vibrodyne
Limit Analysis for Historical Masonry Bridge with CFRP Reinforcements
Full text linkThe paper deals with the collapse behavior of a historical masonry arch bridge subject to combined seismic loads, by means of the limit analysis and shakedown theorems. The assessment of the collapse loads and shakedown multiplier have been analyzed using lower bound theorems of the limit analysis and shakedown theory. The retrofitting consists in the application of CFRP strips on the extrados of the arch with a significant increase of the collapses and shakedown multipliers. The results of a FEM analysis have been achieved with ANSYS code involving the non-linear material behavior and the structural role of the spandrel walls and filling
Application of Artificial Intelligence to Support Design and Analysis of Steel Structures
No full textIn steel structural engineering, artificial intelligence (AI) and machine learning (ML) are improving accuracy, efficiency, and automation. This review explores AI-driven approaches, emphasizing how AI models improve predictive capabilities, optimize performance, and reduce computational costs compared to traditional methods. Inverse Machine Learning (IML) is a major focus since it helps engineers to minimize reliance on iterative trial-and-error by allowing them to identify ideal material properties and geometric configurations depending on predefined performance targets. Unlike conventional ML models that focus mostly on forward predictions, IML helps data-driven design generation, enabling more adaptive engineering solutions. Furthermore, underlined is Explainable Artificial Intelligence (XAI), which enhances model transparency, interpretability, and trust of AI. The paper categorizes AI applications in steel construction based on their impact on design automation, structural health monitoring, failure prediction and performance evaluation throughout research from 1990 to 2025. The review explores challenges such as data limitations, model generalization, engineering reliability, and the need for physics-informed learning while examining AI’s role in bridging research and real-world structural applications. By integrating AI into structural engineering, this work supports the adoption of ML, IML, and XAI in structural analysis and design, paving the way for more reliable and interpretable engineering practices
M-N interaction effect on the frames failure mechanisms
No full textThe collapse factor is a significant parameter in the framework of the safety assessment and economical design of ductile structures. This fact draws attention to the necessity of a careful assessment of the limit analysis approaches. The kinematics in these structures arises in fact from the actual rotation of the plastic hinges under axial force and bending moment. It can be shown that it is possible to obtain a reliable tool capable of competing with computationally expensive methodologies. The application of the methods of limit analysis involves a simplified and idealised model of the structure and, notwithstanding the fact that hundreds of papers have been devoted to the topic, some consequences of apparently unimportant simplifications still seem to have not been properly and firmly highlighted. This paper investigates the ultimate load and collapse modes of steel frames under combined vertical and horizontal forces through limit analysis
Design and optimization of pre-tension forces in cable-stayed bridges
No full textThe construction of cable-stayed bridges is characterized by several constructive phases in which geometry, boundaries and loads vary significantly in the time, causing a change in the stresses and deformations, up until the final configuration is reached. This work presents a numerical procedure for the optimal design of the cable pretensioning in cable-stayed bridges, with the aim of obtaining a desired distribution of bending moments along the deck. An optimal pre-tensioning sequence is useful for controlling stress and strain levels during the different construction phases of the examined structures. Two case studies show the potential of the proposed procedure when dealing with technically relevant examples
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